Apparatus and method for manufacturing polymeric fibrils

ABSTRACT

An electrospinning apparatus is described. The electrospinning apparatus has a rotary nozzle mechanism that moves simultaneously along a non-linear track for forming polymeric fibrils, so that the polymeric fibrils can be piled to form a uniform web on a receiving carrier from any receiving angle. Therefore, the electrospinning apparatus resolves problems of the prior polymeric fibrils, such as various distribution and slow production rate. In addition, a method of manufacturing polymeric fibrils in the aforementioned electrospinning apparatus is further described.

RELATED APPLICATIONS

The present application is based on, and claims priority from, TaiwanApplication Serial Number 93122776, filed Jul. 29, 2004, the disclosureof which is hereby incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to an electrospinning apparatus and amethod for manufacturing polymeric fibrils in mass production, and moreparticularly, to an electrospinning apparatus with a rotary nozzlemechanism and a method for manufacturing polymeric fibrils.

BACKGROUND OF THE INVENTION

The electrospinning technology is for manufacturing nanofibers. Theprinciple of the electrospinning technology is to provide a drivingforce generated by an electrical field between a positive and a negativeelectrodes, so as to overcome surface tension and viscosity of a polymersolution. In addition, streams of polymer solution ejected from a nozzleare mutually repulsive because they carry the same charge; when thesolvent evaporates, ultra-thin fibers are formed. The process is alsocalled fiber electrospinning. Comparing with the fibers produced by theprior spinning technology in diameters of several micrometers (μm), thepolymeric fibrils produced by the electrospinning technology can achievea purpose of fiber thinning, due to mechanical and electrostatic forcesduring the electrospinning process. Moreover, the fabric spun by theelectrospinning method enjoys the advantages of having a more favored inhigher porosity, larger surface area, and smaller pore size than thoseof conventional fabrics.

In U.S. Pat. No. 6,616,435, an apparatus of a polymer web formed by anelectrospinning process is disclosed. The apparatus comprises: a barrelstoring at least one kind of polymer material in a liquid state; a pumppressurizing and supplying the polymer material in the liquid statestored in the barrel; a spinning part for injecting the polymer materialin the liquid state supplied by the pump through at least one chargednozzle and manufacturing thin fibers; a high voltage generator providingan electric charge for charging the polymer material discharged throughthe at least one nozzle of the spinning part to have one polarity; and acollector for piling and transferring the thin fibers to form thepolymer web. The electrospinning apparatus has an automatic productionability operated with a plane conveyer belt.

In U.S. Pat. No. 6,110,590, a silk nanofiber composite network producedby forming a solution of silk fiber and hexafluroisopropanol isdisclosed. The silk solution has a concentration of about 0.2 to about1.5 weight percent silk in hexafluroisopropanol, thereby forming anon-woven network of nanofibers having a diameter in the range of about2 to about 2000 nanometers (nm) for medical use.

In U.S. Publication No. 2003/0211135, a method of producing a compositefilm fibrous web having diameters averaging less than 100 micrometers bymoving nozzles along X-Y axes is disclosed. The resultant product can beapplied in, for example, fuel cells and medical supplies.

In brief, the polymeric fibrils can be produced with various diametersby controlling the system parameters of the electrospinning apparatussuch as, for example, molecular weight, viscosity, conductivity, surfacetension of the polymer solution, controlling operation parameters suchas potential of the discharging electrode, flow rate of the polymersolution, the distance between electrodes, and temperature and humidityin the operation environment. However, an uneven web is produced byreciprocating the above nozzle. Reference is made to FIG. 1, whichdepicts a track of a nozzle on the receiving carrier in the prior art.When the nozzle 101 ejects the polymeric fibrils in a reciprocating way,the receiving carrier goes in a direction 109 vertical to the movingdirection of the nozzle. The resultant web is formed with densepolymeric fibrils distributed in a region M and thin polymeric fibrilsdistributed out of the region M. Reference is made to FIG. 2, whichdepicts another track of another nozzle on the receiving carrier in theprior art. When the nozzle 101 also ejects the polymeric fibrils inreciprocating way, the receiving carrier goes in a direction 109vertical to the moving direction of the nozzle. The resultant web isformed with dense polymeric fibrils distributed in a region N and thinpolymeric fibrils distributed out of the region N.

In addition to the problem of unevenness in the polymer web produced bythe U.S. Pat. No. 6,616,435, there is further an issue of slowproduction rates for other technologies. For examples, a unit ofequipment disclosed in U.S. Pat. No. 6,110,590 is merely an experimentalone in the laboratory without continuous production ability. Moreover,the equipment disclosed in U.S. Publication No. 2003/0211135 has a slowproduction rate for the purpose of uniform distribution. Furthermore,the web produced by such polymeric fibrils produced by the above methodscannot completely satisfy the requirements for thinner diameter, uniformdistribution, and higher production rate.

Hence, there is an urgent need for an electrospinning apparatus andmethod of manufacturing polymeric fibrils, so as to resolve the problemsof uneven distribution, slow production rate and so on.

SUMMARY OF THE INVENTION

It is an aspect of the present invention to provide an electrospinningapparatus. The electrospinning apparatus utilizes a rotary supportingdevice. A distance between outlets of the polymer solution of the rotarysupporting device can be freely adjusted, and an outlet of the rotarysupporting device moves along a non-linear track, so that the polymericfibrils can be formed as a uniform web. The electrospinning apparatusfurther has a transporting device for producing the uniform webcontinuously or in batches. Therefore, the electrospinning apparatusresolves the problems, such as uneven distribution and slow productionrate, of the prior polymeric fibrils.

It is another aspect of the present invention to provide a rotary nozzlemechanism. The rotary nozzle mechanism is suitable for anelectrospinning apparatus. The rotary supporting device moves along anon-linear track, so that the polymeric fibrils can be formed into auniform web at any receiving angle on a receiving carrier. The rotarysupporting device of the invention improves problems of the priorpolymeric fibrils, such as uneven distribution and slow production rate.

It is a further aspect of the present invention to provide a method ofmanufacturing polymeric fibrils utilizing a rotary nozzle mechanism formanufacturing the polymeric fibrils. Outlets of the polymer solutionmove along a non-linear track, so that the polymeric fibrils can beformed into a uniform web.

It is a still another aspect of the present invention to provide amethod of manufacturing polymeric fibrils utilizing outlets of thepolymer solution of the rotary supporting device simultaneously movingalong a non-linear track. The polymeric fibrils can be emitted at anyreceiving angle to form a uniform web on a collector, while employing arotary supporting device of an electrospinning apparatus manufacturingultra-thin polymeric fibrils. Moreover, the method of manufacturingpolymeric fibrils is also performed continuously or in batches, andhence capable of achieving automatic production.

According to the aforementioned aspect of the present invention, anelectrospinning apparatus is provided. The electrospinning apparatuscomprises at least one rotary supporting device including at least oneoutlet, wherein a discharging electrode is disposed in the outlet and apolymer solution is introduced by a duct. A collector is located belowthe rotary supporting device and has a surface to face the outlet. Whena voltage is applied to the discharging electrode, the polymer solutionis ejected from the outlet, so as to form charged polymeric fibrils andpile the same on a receiving carrier above a collector. Simultaneously,the receiving carrier advances along a direction and the outlet movesalong a non-linear track, thus forming a web on a surface of thereceiving carrier.

Preferably, the rotary supporting device is at least one supporting armor a plate.

Preferably, the non-linear track is a circular track, an elliptic trackor a wavy track.

Preferably, the other end of the rotating shaft serves as a center forthe end of the rotating shaft, simultaneously revolving the rotatingshaft to eject the polymeric fibrils at a tilt angle with respect to avertical direction or at a fixed angle.

Preferably, nozzles are arranged on one end and the other end of therotary supporting device, respectively, the outlets are separated fromeach other by a space, and the space is freely adjustable and less thanor equal to the supporting device in length.

Preferably, a shape of the collector is a dish, a circle, an ellipse, arectangle, a three-dimensional shape or combinations thereof.

According to another aspect of the present invention, a rotary nozzlemechanism suitable for an electrospinning apparatus is provided. Therotary nozzle mechanism comprises a rotating shaft that spins around anaxis thereof and at least one supporting device that has at least oneoutlet and is pivoted on an end of the rotating shaft. The outlet iselectrically connected to a discharging electrode and with a polymersolution is introduced by a duct. When a voltage is applied to thedischarging electrode for ejecting the polymer solution from the outlet,charged polymeric fibrils are formed and piled on a receiving carrierabove a collector, while the receiving carrier advances simultaneouslyalong a direction and the outlet moves along a non-linear track, thusforming a web on a surface of the receiving carrier.

According to the further aspect of the present invention, a method ofmanufacturing polymeric fibrils is provided. A rotary nozzle mechanismis firstly provided, which comprises a rotating shaft that spins aroundan axis thereof, and at least one supporting device that has at leastone outlet and is pivoted on an end of the rotating shaft. The outlet iselectrically connected to a discharging electrode and a polymer solutionis introduced by a duct. Then, when a voltage is applied to thedischarging electrode for ejecting the polymer solution from the outlet,charged polymeric fibrils are formed and piled on a receiving carrierabove a collector. Simultaneously, the receiving carrier advances alonga direction and the outlet moves along a non-linear track, thus forminga web on a surface of the receiving carrier.

According to the still another aspect of the present invention, there isprovided a method of manufacturing polymeric fibrils is provided. Anelectrospinning apparatus is first provided, which comprises at leastone rotary supporting device including at least one outlet, wherein adischarging electrode is disposed in the outlet and a polymer solutionis introduced by a duct; and a collector located below the rotarysupporting device. Then, a voltage is applied to the dischargingelectrode for ejecting the polymer solution from the outlet, formingcharged polymeric fibrils and piling the same on a receiving carrierabove a collector. Simultaneously, the receiving carrier advances alonga direction and the outlet moves along a non-linear track, thus forminga web on a surface of the receiving carrier.

The method of manufacturing polymeric fibrils performed by employing theelectrospinning apparatus utilizes a rotary nozzle mechanism movingalong a non-linear track, so that the ultra-thin polymeric fibrils canbe formed at any receiving angle, such as horizontal, vertical or anyangle, to be piled to form the uniform web on the receiving carrier.Therefore, the problems of the prior polymeric fibrils, such as variousdistribution and slow production rate, can be resolved.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 depicts a track of a nozzle on the receiving carrier in the priorart;

FIG. 2 depicts another track of another nozzle on the receiving carrierin the prior art;

FIG. 3 is a flow chart of the method of manufacturing polymeric fibrilsaccording to a preferred embodiment of the invention;

FIG. 4 depicts a side diagram of the electrospinning apparatus accordingto a preferred embodiment of the invention;

FIG. 5 depicts a cross-sectional view along the line AA′ in FIG. 4;

FIGS. 6 to 10 depict bottom views of the rotary nozzle mechanismaccording to several preferred embodiments of the present invention;

FIG. 11 depicts a rotary nozzle mechanism according to anotherembodiment of the present invention;

FIG. 12 depicts a track of a nozzle on the receiving carrier accordingto an embodiment of the present invention;

FIG. 13 depicts a track of a nozzle on the receiving carrier accordingto an another embodiment of the present invention; and

FIG. 14 depicts a schematic diagram of a solvent recycling facilityaccording to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a method of manufacturing polymericfibrils. Reference is made to FIG. 3, which is a flow chart of themethod of manufacturing polymeric fibrils according to a preferredembodiment of the invention. A rotary nozzle mechanism is provided asillustrated in the step 151, which is located in an electrospinningapparatus and comprises a rotating shaft that spins around an axisthereof, and at least one supporting device that has at least one outletand is pivoted on an end of the rotating shaft. In another example, atleast one rotary supporting device is also provided, which is alsolocated in the electrospinning apparatus and has at least one outlet.The outlet is electrically connected to a discharging electrode and apolymer solution is introduced by a duct. The rotating shaft spinsaround an axis thereof. Then, as illustrated in the step 153, a voltageis applied to the discharging electrode for ejecting the polymersolution from the outlet, so as to form charged polymeric fibrils andpile the same on a receiving carrier above a collector. Simultaneously,the receiving carrier advances along a direction and the outlet movesalong a non-linear track, thus forming a web on a surface of thereceiving carrier, as illustrated in the step 155.

For operating in coordination with the aforementioned process, theinvention further provides an electrospinning apparatus, which utilizesa rotary nozzle mechanism moving along a non-linear track, so that theresultant nano-scale polymeric fibrils can be piled to form a uniformweb on the receiving carrier at any receiving angle. The followingelectrospinning apparatus of the present invention is illustrated indetail by accompanying FIGS. 4 to 14.

Reference is made to FIG. 4, which depicts a side diagram of theelectrospinning apparatus according to a preferred embodiment of theinvention. The electrospinning apparatus 200 comprises a rotary nozzlemechanism 210 comprising a rotating shaft 211 that spins around an axis213 thereof along a direction indicated by an arrow 215. A middle pointof a supporting device 211, such as a supporting arm, is pivoted on anend of the rotating shaft 211. Alternatively, a plurality of supportingarms serve as supporting devices 211 and are pivoted on the same end ofthe rotating shaft 211 by respective middle points of the respectivesupporting arms, details of which are discussed later. At least oneoutlet is disposed on the supporting device 211. The outlet that isprovided, such as a nozzle 231 or other type of outlet, is freelydisposed on the supporting device 211. The outlet of the nozzle 231 iselectrically connected to a discharging electrode 233 and a polymersolution is introduced from a polymer solution storing tank 251 by aduct 241.

A collector 271 is located below the rotary nozzle mechanism 210 asshown in FIG. 4. The collector 271 is typically grounded. When a voltageprovided by a high-voltage power supply 261 is applied to thedischarging electrode 233 of the rotary nozzle mechanism 210, a electricfield is generated between the discharging electrode 233 and thecollector 271, for ejecting the polymer solution 251 from the outlet ofthe nozzle 231, so as to form charged polymeric fibrils 277 and pile thesame in the direction of the collector 271. A surface of the collector271 facing the rotary nozzle mechanism 210 has a guiding pore forexhausting air (not shown), aiding in the proper stacking of thepolymeric fibrils 277. The guiding pore for exhausting air is providedby a structure that is hollow and has pores, and a material of thestructure may be a metal or a metal-containing fabric.

As shown in FIG. 4, a receiving carrier 273 is located above thecollector 271 in a predetermined height H for piling the polymericfibrils 277, and the predetermined height H is in a range of 0 to 1meter. A material of the receiving carrier 273 is not limited butdepends on the requirements of the process. In addition, a surface 275of the receiving carrier 273 may be a plane or a three-dimensionalshape, and the surface 275 of the receiving carrier 273 is perforated ornot. The polymeric fibrils 277 are formed into a web on the receivingcarrier 273, and then dried at room temperature. Since the poresremaining within the web are very small, the receiving carrier with theweb can serve as a high-efficiency filtration material. For instance,when the surface 275 of the receiving carrier 273 is a plane, thereceiving carrier with the web can be manufactured into, for example,flat facemasks and filter sheets. When the surface 275 of the receivingcarrier 273 is a three-dimensional shape, the receiving carrier with theweb can be manufactured into, for example, three-dimensional facemasks,filtrating cartridges, and biomedical materials.

The electrospinning apparatus 200 of the present invention furtherutilizes a transporting device 280 for continuously transporting thereceiving carrier 273 in a direction indicated by an arrow 295. As shownin the configuration of FIG. 4, the transporting device 280 comprisesrollers 281, 283, 285, 287, 291 and a roller presser 289. The roller 281rolls up the whole tape of the receiving carrier 273. The rollers 283,285 and a conveyer mesh belt 293 lead the receiving carrier 273 to pilethe polymeric fibrils 277 above the collector 271 in the directionindicated by the arrow 295, thereby forming the web on the surface 275of the receiving carrier 273. And optionally, the roller presser 289serves to press a face fabric 297 onto the receiving carrier 273 withthe web, for forming a composite filtration material 299, in which theroller 287 rolls up the whole tape of the face fabric 297. Afterwards,the resultant composite filtration material 299 is received by theroller 291. The electrospinning apparatus 200 with the transportingdevice 280 can be operated continuously or in batches, and hence iscapable of meeting the requirement for automatic production.

Reference is made to FIG. 5, which depicts a cross-sectional view alongthe line AA′ in FIG. 4. In an embodiment of the present invention, therotary nozzle mechanism 210 can be fixed on a stand 300. The stand 300comprises a upper portion 301 and a support 303 for support thereof. Theupper portion 301 serves to fix the rotary nozzle mechanism 210. Thepolymer solution storing tank 251 is freely located on the support 303,and the support 303 can be designed to be moveable. The polymer solutionstoring tank 251 is connected to the outlet of the nozzle 231 by theduct (not shown). A motor 305 is further located on the top of the upperportion 301, and serves to drive the rotating shaft 211 of the rotarynozzle mechanism 210, so as to make the rotating shaft 211 rotate freelyin one direction or more.

In FIG. 5, one end and the other end of the supporting device 221pivoted on the rotating shaft 211 have nozzles 231, respectively, andthe nozzles 231 are separated by a space d from each other. The space dis freely adjustable depending on requirements. For instance, thedistance d is less than or equal to the supporting device 221 in lengthD. Moreover, nozzles 235 can be located underlying the connection of thesupporting device 221, in which the outlets of the nozzles 235 cancompress adequate gas to adjust a rate of extruding the polymericfibrils.

In a preferred embodiment of the present invention, the nozzle 231 isarranged on only one end of the supporting device 221, and performs arevolving motion driven by the rotating shaft 211 in a directionindicated by an arrow 215, as shown in a bottom view of FIG. 6. Inanother preferred embodiment of the present invention, the nozzles 231are arranged on both ends of the supporting device 221, and perform therevolving motion driven by the rotating shaft 211 in the directionindicated by the arrow 215, as shown in a bottom view of FIG. 7. In afurther preferred embodiment of the present invention, the nozzles 231are arranged respectively on both ends of two supporting devices 221,and perform the revolving motion driven by the rotating shaft 211 in thedirection indicated by the arrow 215, as shown in a bottom view of FIG.8. It is reasonable to derive that the nozzles 231 are arrangedrespectively on both ends of three or four supporting devices 221, andperform the revolving motion driven by the rotating shaft 211 in thedirection indicated by the arrow 215, as shown in bottom views of FIGS.9 and 10. However, as is understood by a person skilled in the art, theforegoing configurations of the rotary nozzle mechanism 210 of thepresent invention are merely illustrated exemplarily rather thanlimiting the number and the configuration of the nozzles 231 and thesupporting devices 221. For example, the supporting device 221 can beany shape of a plate in addition to the supporting arm, so as to freelydispose nozzles 231 on the plate-form of the supporting device 221.

It is worth mentioning that the rotary nozzle mechanism 210 of thepresent invention can rotate freely in one direction or more, so thatthe outlet of the nozzle 231 moves along a non-linear track. Thenon-linear track may be a circular track, an elliptic track or a wavytrack. Therefore, the rotary nozzle mechanism 210 of the presentinvention utilizes gravitational and centrifugal forces to prevent thebeading effect occurring in conventional polymeric fibril formation.Reference is made to FIG. 4 again; the rotating shaft 211 of the rotarynozzle mechanism 210 spins around the axis 231 in the directionindicated by the arrow 215. The axis 213 is vertical. Reference is madeto FIG. 11, which depicts a rotary nozzle mechanism according to anotherembodiment of the present invention. The rotating shaft 211 of therotary nozzle mechanism 210 spins around the axis 231 thereof in thedirection indicated by the arrow 215. The rotating shaft 211 eitherspins around the axis 213 tilted at a tilt angle θ with respect to avertical axis 217, or spins at the tilt angle θ and the axis 231revolves simultaneously at the tilt angle θ with respect to a verticaldirection. The tilt angle θ is in a range of 0 to 45 degrees. When theelectrospinning process is performed by using the rotary nozzlemechanism 210 as shown in FIG. 4 or FIG. 11 in conjunction withcontinuous transportation of the receiving carrier, the polymericfibrils ejected from the outlet of the nozzle 231 exhibit the circular,elliptic track as shown in FIG. 12, or the wavy track as shown in FIG.13 on the receiving carrier.

The rotary nozzle mechanism of the present invention utilizesgravitational, electrostatic and centrifugal forces to produce thethinner polymeric fibrils, and a diameter thereof is in a range of 2 to2000 nm, and a basic weight thereof is equal to 0.3 g/m³ or more.

In the aforementioned examples, the tilt angle of the rotary nozzlemechanism of the present invention is freely adjustable, so that thepolymeric fibrils can be formed from any receiving angle, such ashorizontal, vertical or any angle, to be piled to form the uniform webon the receiving carrier. However, in another example, the configurationof the receiving carrier 273 and the transporting device 280 as shown inFIG. 4 can be adjusted, so that the receiving carrier 273 can be formedfrom any receiving angle, such as horizontal, vertical or any angle, soas to pile the polymeric fibrils 277 and form the uniform web onto thereceiving carrier 273.

Additionally, for satisfying the requirement of environmentalprotection, a solvent recycling facility can recycle organic solventsused in the process of the polymeric fibrils of the present invention.Reference is made to FIG. 14, which depicts a schematic diagram of asolvent recycling facility according to a preferred embodiment of thepresent invention. The process of the polymeric fibrils of the presentinvention can be performed in a closed process chamber 400, and a wastegas that contains organic solvents generated in the process can betransported to a condensation device 420 by a air duct 411 in adirection indicated by an arrow 401, and condense therein. A spraydevice 421 can be located in the condensation device 420, so that thesprayed stream can condense the waste gas to generate waste water 423containing organic solvents. The condensed waste gas can be transportedto a gas filtration device 430 by a exhaust 427 along to a direction ofan arrow 425. In the gas filtration device 430, the condensed waste gasstill generates some condensate liquid 435, and the condensate liquid435 is recycled through a duct 437 into the condensation device 420. Thewaste is absorbed and filtered by a filter bed 433, and then becomesclean air 440 and is exhausted into the atmosphere directly.

The exemplary electrospinning apparatus and method of manufacturingpolymeric fibrils of the present invention is illustrated in conjunctionwith several following embodiments.

EXAMPLE 1

The nozzles are freely arranged on both ends of the supporting device ofthe rotary nozzle mechanism of the electrospinning apparatus, where20-gauge needles, for example, serve as the nozzles and thepredetermined height H between the collector and the receiving carrieris, for example, 40 centimeters (cm). A rolling speed of a planereceiving carrier is less than 1 meter per minute. A concentration ofthe polymer solution is in a ratio such as 15 to 25 weight percentpolyacrylonitrile (PAN) to dimethyl formamide (DMF), and preferably, ina ratio of 15 to 20 weight percent. The relationship in ratio andviscosity of the PAN and the DMF is shown in TABLE 1 as follows. TABLE 1PAN/DMF Concentration Viscosity (g/ml) (wt %) (cp) 15/100 15 4250 20/10020 12000 25/100 25 48000

When a voltage of about 40 kilovolts (kV) is applied to the dischargingelectrode, a web is formed by the polymeric fibrils on the planereceiving carrier, and then dried at room temperature. The polymericfibrils are less than 0.8 micrometers (μm) in diameter. The motion speedis more than 30 cm per minute in the width of 60 cm. The ejection speedof the polymer solution is less than 5 ml per minute.

EXAMPLE 2

The nozzles are freely arranged on both ends of the supporting device ofthe rotary nozzle mechanism of the electrospinning apparatus, where20-gauge needles, for example, serve as the nozzles and thepredetermined height H between the collector and the receiving carrieris, for example, 40 cm. A rolling speed of a cylinder receiving carrieris 200 rpm. A concentration of the polymer solution is in a ratio suchas 15 weight percent of PAN to DMF.

When a voltage of about 40 kV is applied to the discharging electrode, aweb is formed by the polymeric fibrils on the cylinder receivingcarrier, and then dried at room temperature. The polymeric fibrils areless than 0.8 μm in diameter. The ejection speed of the polymer solutionis 5 ml per minute. The motion speed is about 4.7 cm per minute in thewidth of 60 cm. The above motion speed is based on a single tube of thepolymer solution for manufacturing the polymeric fibrils. When anautomatic production is performed, multiple tubes of the polymersolution can be employed for manufacturing the polymeric fibrils. Forexample, 8 tubes of the polymer solution are used to manufacture thepolymeric fibrils, and the motion speed of the polymeric fibrils is upto 37.6 cm per minute in the width of 60 cm.

EXAMPLE 3

The nozzles are freely arranged on both ends of the supporting device ofthe rotary nozzle mechanism of the electrospinning apparatus, where20-gauge needles serve as the nozzles and the predetermined height Hbetween the collector and the receiving carrier is, for example, 40 cm.When a voltage of about 40 volts is applied to the dischargingelectrode, a web is formed by the polymeric fibrils on thethree-dimensional receiving carrier. A dioctyl phthalate (DOP)filtration efficiency of the receiving carrier without the web formedthereon is in a range of 40 to 50 percent. However, a filtrationefficiency of the receiving carrier with the web formed thereon israised to 85 to 88 percent.

Therefore, according to the aforementioned preferred embodiments, oneadvantage of the method of manufacturing polymeric fibrils performed byemploying the electrospinning apparatus of the present invention, is theuse of the rotary nozzle mechanism moving along a non-linear track, sothat the polymeric fibrils can be formed at any receiving angle, such ashorizontal, vertical or any angle, to be piled to form the uniform webon the receiving carrier. Therefore, the problems of the prior polymericfibrils, such as various distribution and slow production rate, can beresolved.

As is understood by a person skilled in the art, the foregoing preferredembodiments of the present invention are illustrated of the presentinvention rather than limiting of the present invention. It is intendedto cover various modifications and similar arrangements included withinthe spirit and scope of the appended claims. Therefore, the scope ofwhich should be accorded to the broadest interpretation so as toencompass all such modifications and similar structure.

1. An electrospinning apparatus, comprising: at least one rotarysupporting device including at least one outlet, wherein a dischargingelectrode is disposed in the outlet and a polymer solution is introducedby a duct; and a collector located below the rotary supporting deviceand having a surface to face the outlet; wherein when a voltage isapplied to the discharging electrode for ejecting the polymer solutionfrom the outlet, charged polymeric fibrils are formed and piled on areceiving carrier above the collector, while the receiving carriersimultaneously advances along a direction and the outlet moves along anon-linear track, thus forming a web on a surface of the receivingcarrier.
 2. The electrospinning apparatus according to claim 1, whereinthe rotary supporting device is at least one supporting arm.
 3. Theelectrospinning apparatus according to claim 1, wherein the rotarysupporting device is a plate.
 4. The electrospinning apparatus accordingto claim 1, wherein the polymer solution is provided from a polymersolution storing tank.
 5. The electrospinning apparatus according toclaim 1, wherein the non-linear track is a circular track, an elliptictrack or a wavy track.
 6. The electrospinning apparatus according toclaim 5, wherein the rotary supporting device is further connected to anend of a rotating shaft.
 7. The electrospinning apparatus according toclaim 6, wherein the rotating shaft spins at a tilt angle with respectto a vertical direction.
 8. The electrospinning apparatus according toclaim 7, wherein the tilt angle is in a range of about 0 to 45 degrees.9. The electrospinning apparatus according to claim 8, wherein anotherend of the rotating shaft serves as a center for the end of the rotatingshaft, so as to simultaneously revolve the rotating shaft at the tiltangle.
 10. The electrospinning apparatus according to claim 1, whereinthe outlets are separated from each other by a space, and the space isless than or equal to the rotary supporting device in length.
 11. Theelectrospinning apparatus according to claim 1, wherein the polymericfibrils are about 2 to 2000 nanometers (nm) in diameter.
 12. Theelectrospinning apparatus according to claim 1, wherein a shape of thecollector is a dish, a circle, an ellipse, a rectangle, athree-dimensional shape or a combination thereof.
 13. Theelectrospinning apparatus according to claim 1, wherein the surface ofthe collector has a guiding pore for exhausting air.
 14. Theelectrospinning apparatus according to claim 13, wherein the guidingpore for exhausting air is provided by a hollow structure with pores.15. The electrospinning apparatus according to claim 14, wherein amaterial of the structure is selected from the group consisting of ametal and a metal-containing fabric.
 16. The electrospinning apparatusaccording to claim 1, wherein the receiving carrier is located above thecollector at a predetermined height, and the predetermined height is ina range of about 0 to 1 meter.
 17. The electrospinning apparatusaccording to claim 1, wherein the surface of the receiving carrier is aplane or a three-dimensional shape.
 18. The electrospinning apparatusaccording to claim 1, wherein the surface of the receiving carrier isperforated.
 19. The electrospinning apparatus according to claim 1,further comprising a transporting device for continuously transportingthe receiving carrier along the direction.
 20. A rotary nozzlemechanism, suitable for an electrospinning apparatus, the rotary nozzlemechanism comprising: a rotating shaft spinning around an axis thereof;and at least one supporting device including at least one outlet andpivoted on an end of the rotating shaft, wherein the outlet iselectrically connected to a discharging electrode and a polymer solutionis introduced by a duct; wherein when a voltage is applied to thedischarging electrode for ejecting the polymer solution from the outlet,charged polymeric fibrils are formed and piled on a receiving carrierabove a collector, while the receiving carrier advances simultaneouslyalong a direction and the outlet moves along a non-linear track, thusforming a web on a surface of the receiving carrier.
 21. The rotarynozzle mechanism according to claim 20, wherein the supporting device isat least one supporting arm.
 22. The rotary nozzle mechanism accordingto claim 20, wherein the supporting device is a plate.
 23. The rotarynozzle mechanism according to claim 20, wherein the non-linear track isa circular track, an elliptic track or a wavy track.
 24. The rotarynozzle mechanism according to claim 23, wherein the rotating shaft spinsat a tilt angle with respect to a vertical direction.
 25. The rotarynozzle mechanism according to claim 24, wherein the tilt angle is in arange of about 0 to 45 degrees.
 26. The rotary nozzle mechanismaccording to claim 25, wherein an other end of the rotating shaft servesas a center for the end of the rotating shaft, so as to simultaneouslyrevolve the rotating shaft at the tilt angle.
 27. The rotary nozzlemechanism according to claim 20, wherein the outlets are separated fromeach other by a space, and the space is less than or equal to thesupporting device in length.
 28. The rotary nozzle mechanism accordingto claim 20, wherein the polymeric fibrils are about 2 to 2000nanometers in diameter.
 29. The rotary nozzle mechanism according toclaim 20, wherein a shape of the collector is a dish, a circle, anellipse, a rectangle, a three-dimensional shape or a combinationthereof.
 30. The rotary nozzle mechanism according to claim 20, whereina surface of the collector facing the rotary nozzle mechanism has aguiding pore for exhausting air.
 31. The rotary nozzle mechanismaccording to claim 30, wherein the guiding pore for exhausting air isprovided by a hollow structure with pores.
 32. The rotary nozzlemechanism according to claim 31, wherein a material of the structure isselected from the group consisting of a metal and a metal-containingfabric.
 33. The rotary nozzle mechanism according to claim 20, whereinthe receiving carrier is located above the collector at a predeterminedheight, and the predetermined height is in a range of about 0 to 1meter.
 34. The rotary nozzle mechanism according to claim 20, whereinthe surface of the receiving carrier is a plane or a three-dimensionalshape.
 35. The rotary nozzle mechanism according to claim 20, whereinthe surface of the receiving carrier is perforated.
 36. A method ofmanufacturing polymeric fibrils, comprising: providing a rotary nozzlemechanism, comprising: a rotating shaft spinning around an axis thereof;and at least one supporting device including at least an outlet andpivoted on an end of the rotating shaft, wherein the outlet iselectrically connected to a discharging electrode and a polymer solutionis introduced by a duct; and applying a voltage to the dischargingelectrode for ejecting the polymer solution from the outlet, chargedpolymeric fibrils being formed and piles on a receiving carrier above acollector, while the receiving carrier simultaneously advances along adirection and the outlet moves along a non-linear track, wherein a webforms on a surface of the receiving carrier.
 37. The method ofmanufacturing polymeric fibrils according to claim 36, wherein thesupporting device is at least one supporting arm.
 38. The method ofmanufacturing polymeric fibrils according to claim 36, wherein thesupporting device is a plate.
 39. The method of manufacturing polymericfibrils according to claim 36, wherein the non-linear track is acircular track, an elliptic track or a wavy track.
 40. The method ofmanufacturing polymeric fibrils according to claim 39, wherein therotating shaft spins at a tilt angle with respect to a verticaldirection.
 41. The method of manufacturing polymeric fibrils accordingto claim 40, wherein the tilt angle is in a range of about 0 to 45degrees.
 42. The method of manufacturing polymeric fibrils according toclaim 41, wherein another end of the rotating shaft serves as a centerfor the end of the rotating shaft, the rotating shaft simultaneouslyrevolving at the tilt angle.
 43. The method of manufacturing polymericfibrils according to claim 36, wherein the outlets are separated fromeach other by a space, and the space is less than or equal to thesupporting device in length.
 44. The method of manufacturing polymericfibrils according to claim 36, wherein the polymeric fibrils are about 2to 2000 nanometers in diameter.
 45. The method of manufacturingpolymeric fibrils according to claim 36, wherein a shape of thecollector is a dish, a circle, an ellipse, a rectangle, athree-dimensional shape or a combination thereof.
 46. The method ofmanufacturing polymeric fibrils according to claim 36, wherein a surfaceof the collector facing the rotary nozzle mechanism has a guiding porefor exhausting air.
 47. The method of manufacturing polymeric fibrilsaccording to claim 46, wherein the guiding pore for exhausting air isprovided by a hollow structure with pores.
 48. The method ofmanufacturing polymeric fibrils according to claim 47, wherein amaterial of the structure is selected from the group consisting of ametal and a metal-containing fabric.
 49. The method of manufacturingpolymeric fibrils according to claim 36, wherein the receiving carrieris located above the collector at a predetermined height, and thepredetermined height is in a range of about 0 to 1 meter.
 50. The methodof manufacturing polymeric fibrils according to claim 36, wherein thesurface of the receiving carrier is a plane or a three-dimensionalshape.
 51. The method of manufacturing polymeric fibrils according toclaim 36, wherein the surface of the receiving carrier is perforated.52. A method of manufacturing polymeric fibrils, comprising: providingan electrospinning apparatus, comprising: at least one rotary supportingdevice including at least one outlet, wherein a discharging electrode isdisposed in the outlet and a polymer solution is introduced by a duct;and a collector located below the rotary supporting device; and applyinga voltage to the discharging electrode for ejecting the polymer solutionfrom the outlet, charged polymeric fibrils being formed and piled on areceiving carrier above the collector, while the receiving carriersimultaneously advances along a direction and the outlet moves along anon-linear track, wherein a web is formed on a surface of the receivingcarrier.
 53. The method of manufacturing polymeric fibrils according toclaim 52, wherein the rotary supporting device is at least onesupporting arm.
 54. The method of manufacturing polymeric fibrilsaccording to claim 52, wherein the rotary supporting device is a plate.55. The method of manufacturing polymeric fibrils according to claim 52,wherein the polymer solution is provided by a polymer solution storingtank.
 56. The method of manufacturing polymeric fibrils according toclaim 52, wherein the non-linear track is a circular track, an elliptictrack or a wavy track.
 57. The method of manufacturing polymeric fibrilsaccording to claim 56, wherein the rotary supporting device is furtherconnected to an end of a rotating shaft.
 58. The method of manufacturingpolymeric fibrils according to claim 57, wherein the rotating shaftspins at a tilt angle with respect to a vertical direction.
 59. Themethod of manufacturing polymeric fibrils according to claim 58, whereinthe tilt angle is in a range of about 0 to 45 degrees.
 60. The method ofmanufacturing polymeric fibrils according to claim 59, wherein anotherend of the rotating shaft serves as a center for the end of the rotatingshaft, the rotating shaft simultaneously revolving at the tilt angle.61. The method of manufacturing polymeric fibrils according to claim 52,wherein the outlets are separated from each other by a space, and thespace is less than or equal to the supporting device in length.
 62. Themethod of manufacturing polymeric fibrils according to claim 52, whereinthe polymeric fibrils are about 2 to 2000 nanometers in diameter. 63.The method of manufacturing polymeric fibrils according to claim 52,wherein a shape of the collector is a dish, a circle, an ellipse, arectangle, a three-dimensional shape or a combination thereof.
 64. Themethod of manufacturing polymeric fibrils according to claim 52, whereina surface of the collector facing the rotary nozzle mechanism has aguiding pore for exhausting air.
 65. The method of manufacturingpolymeric fibrils according to claim 64, wherein the guiding pore forexhausting air is provided by a hollow structure with pores.
 66. Themethod of manufacturing polymeric fibrils according to claim 65, whereina material of the structure is selected from the group consisting of ametal and a metal-containing fabric.
 67. The method of manufacturingpolymeric fibrils according to claim 52, wherein the receiving carrieris located above the collector at a predetermined height, and thepredetermined height is in a range of about 0 to 1 meter.
 68. The methodof manufacturing polymeric fibrils according to claim 52, wherein thesurface of the receiving carrier is a plane or a three-dimensionalshape.
 69. The method of manufacturing polymeric fibrils according toclaim 52, wherein the surface of the receiving carrier is perforated.70. The method of manufacturing polymeric fibrils according to claim 52,wherein the electrospinning apparatus further comprises a transportingdevice for continuously transporting the receiving carrier along thedirection.